Obesity, type 2 diabetes and related metabolic disorders present a major and growing global public health challenge. These disorders result from a complex interplay between genetic, developmental, behavioural and environmental factors that operate throughout life. The mission of the MRC Epidemiology Unit is to investigate the individual and combined effects of these factors and to develop and evaluate strategies to prevent these diseases and their consequences. In this way, we are working to improve the health of people in the UK and around the world. We are a Medical Research Council Unit embedded as a department of the University of Cambridge School of Clinical Medicine. The Unit is part of the Wellcome – MRC Institute of Metabolic Science (IMS) on the Cambridge Biomedical Campus, where the principle offices and laboratories of the Unit are physically located. Unit Director Professor Nick Wareham is Co-Director of the IMS with Professor Sir Stephen O’Rahilly. Being embedded in the IMS is critical to our aspiration to follow up associations between exposures and metabolic disease outcomes to determine possible causality and mechanisms. The Unit is also a part of Cambridge Population Health Sciences, a three department partnership of the Department of Public Health and Primary Care and the MRC Biostatistics Unit. Collectively, the Partnership pursues a wide range of research across epidemiology, biostatistics, population health and primary care, and delivers the Masters courses in Population Health Sciences.